Ngokomthetho, yonke iwebhusayithi yakhiwe ngokuya ngobuchwepheshe obungu-3; I-HTML, i-CSS ne-Javascript. I-HTML isebenza ngoku-oda izingxenye zezingxenye ezahlukahlukene zesayithi, i-CSS ngendlela lezi zingxenye ezinikezwe ngayo futhi -Javascript imisebenzi eyinkimbinkimbi njengokuphendula ezenzweni zomsebenzisi.
En izindatshana ezedlule Besichazile ukuthi kwakuwuhlaka lweCSS futhi sanikezwa uhlu lokuhle kakhulu esingakusebenzisa kuLinux. Ukuthi indima yeJavascript kunzima kakhulu ukuyichaza, sizokwethula okuncane ngendaba, ngaphambi kokuba sithole ukuphawula ngezinhlaka zayo.
Ulimi lohlelo lweJavascript. Isingeniso esincane
Yini iJavascript?
I-Javascript iyi- ulimi lohlelo olwenziwe ekuqaleni ukumisa amakhasi wewebhu ukuthi angabi yi-static, yize namuhla ukusetshenziswa kwayo kusabalele emikhakheni engahlangene nakancane newebhu.
Lizinhlelo ezibhalwe kuJavascript zibizwa ngokuthi yimibhalo futhi bagijima ngaphakathi komshini obonakalayo owaziwa njengenjini yeJavascript.
Zonke iziphequluli zesimanje zifaka inguqulo yazo yenjini yeJavascript
Ukuphepha kwabasebenzisi, iziphequluli ezahlukahlukene zibeka imingcele kulokho ikhodi yeJavascript engakwenza. Isibonelo, ukufinyelela kwamafayela abucayi kudiski. Noma kunjalo, lokhu kungakhawulelwa ngokwengeziwe kuzinketho zokucushwa ngakunye.
Ukusebenza kwekhodi yeJavascript engaphakathi kwekhasi lewebhu kungokulandelayo:
- Injini yeJavascript efakwe kusiphequluli ifunda ikhodi.
- Ikhodi iguqulelwa olimini lomshini.
- Umshini usebenzisa ikhodi.
Ukuba ulimi lohlelo, iJavascript ingenza imisebenzi enjengale:
- Gcina imininingwane ngaphakathi kokuguqukayo.
- Phatha izintambo zombhalo.
- Qalisa izinhlelo eziphendula imicimbi njengokuchofoza isixhumanisi.
Amandla weJavascript ayanda ngokusebenzisa i-Application Programming Interfaces (APIs)
Ama-API anjalo imitapo yolwazi eyenzelwe imisebenzi ethile lokho kukhulula unjiniyela ekubeni abhale kabusha ikhodi ekhona. Endabeni yeJavascript singakhuluma ngezinhlobo ezimbili ze-APIS
Isiphequluli se-Api
Zigijima ngaphakathi kwesiphequluli bese ziphendula imvelo. Sine, isibonelo:
Imodeli Yento Yedokhumenti (i-DOM): Kwenza kube nokwenzeka ukwenza ukuguqulwa kwekhodi ye-HTML ne-CSS yekhasi ngokuphendula imicimbi ethile. Lokhu kunjalo ngamawebhusayithi asivumela ukuthi sibone ukuthi ikhasi lingavela kanjani kumadivayisi ahlukile.
I-Geolocation APIa: Isetshenziselwa ukuthola indawo yomsebenzisi bese iphendula ngokufanele. Isibonelo, isetshenziswa yiNetflix ukwazi ukuthi yikuphi okuqukethwe ongakubona ezweni lakho noma kuGoogle Maps ukukukhombisa lapho ukhona.
I-Canvas neWebGL: Zikulungele ukuhlela ihluzo ze-2d ne-3d
I-Multimedia APIs: Bavumela ukudluliswa nokwamukelwa kokuqukethwe kwe-multimedia ekhasini lewebhu.
Ama-API wesithathu
Izinsizakalo ezahlukahlukene zewebhu zizama ukuthola abasebenzisi abaningi (futhi kwezinye izimo imininingwane ethe xaxa evela kulabo basebenzisi abazoyithengisa) Yingakho dala izixhumi zokuhlela ukuze onjiniyela bakwazi ukuhlanganisa ukusebenza ukuthi lezi zinsizakalo zihlinzeka kumasayithi angaphandle. Lokhu ngokwesibonelo udaba lwalawo makhasi wewebhu akuvumela ukuthi ubhalise ku-akhawunti yakho ye-Google noma ye-Facebook.
Isebenza kanjani ikhodi yeJavascript ngaphakathi kwewebhusayithi
Okokuqala, kufanele kucaciswe ukuthi iskripthi ngasinye se-JavaScript sisebenza ngaphakathi kwendawo yaso yesikhathi sokusebenza. Kunemvelo yokusebenzisa ithebhu ngayinye (uma sivula amasayithi ahlukile ngaphakathi kwewindi elilodwa) noma ngamawindi ahlukile uma sithanda. Akunasimo lapho axhumana khona nomunye noma, njengoba sishilo, ngohlelo lokusebenza ngaphandle kokungenelela okusebenzayo komsebenzisi.
Okokuqala se ulayisha ikhodi ye-HTML yekhasi lewebhu futhi kwenziwa imodeli yento yedokhumenti ukuze ikhonjiswe kusiphequluli. Izinto ezizonamathiselwa ziyalayishwa ekhasini njengemidiya, izithombe, namashidi wesitayela. Ekugcineni, izitayela zinikezwa izingxenye ezahlukahlukene zekhasi njengoba kunqunywe amashidi wesitayela.
Lapho konke lokhu sekuqediwe, kulapho injini yeJavascript iqala khona kulandela ukulandelana okukhulunywe ngenhla.
Esihlokweni sethu esilandelayo sihamba nohlu oluthenjisiwe lwezinhlaka zeJavascript.